/Engine/Source/Runtime/Engine/Classes/Engine/StreamableManager.h
Calls a StreamableDelegate, this will add to the delayed callback queue depending on s.StreamableDelegateDelayFrames
static void ExecuteDelegate ( const FStreamableDelegate & Delegate, [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< [FStreamableHandle](API\Runtime\Engine\Engine\FStreamableHandle) > AssociatedHandle, const FStreamableDelegate & CancelDelegate )